JPH11241435A - Damper chain assembled body and vibration control device making use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper for a vibration control device having high effect of vibration control at a low cost and the vibration control device. SOLUTION: By means of a chain assembled body 1 bundling 1-dozens of chains as a vibration controlling damper and an impacting body 6 colliding therewith, rough surface treatment is applied to the surface of the chain, or the chains having different chain link pitches are mixed in the chain assembled body. Or, the chain assembled body 1 is constituted of chains and spring. The vibration control device constitutes an added vibration system consisting of weight 4, spring 5, damper and lever 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration control device for suppressing minute vibrations of a beam structure and a floor structure of a civil engineering building structure. In particular, the present invention relates to a structure requiring comfortable walking and livability, such as a bridge, a pedestrian bridge, an artificial ground, or a floor structure of a gymnasium or an auditorium on a floor.

[0002]

2. Description of the Related Art Among structures, such as bridges, pedestrian bridges, artificial ground, and floors of gymnasiums and auditoriums on the floor, comfortable walking and habitability are required. Vibration suppression is important for the comfort of these structures. There are various known techniques for providing a vibration system of a structure with an additional vibration system to control the vibration.

[0003] Humans also have a feeling of discomfort and anxiety,
The vibration is about 0.1 g (g: gravitational acceleration) or more and about 2 Hz. If this is regarded as a simple sine wave, the amplitude is about 1 to 5 mm. In order to suppress such minute amplitude, there is a method of amplifying vibration by an additional vibration system and absorbing vibration energy by a damper.

For example, Japanese Patent Application Laid-Open No. Hei 8-120609 discloses a technique for increasing the vibration damping effect of minute vibration by providing a mechanism for expanding the vibration of the weight by leverage and absorbing the vibration with a damper. Although the technique disclosed in the publication does not specify a damper to be used, it seems that a cylinder type oil damper or the like is assumed by estimating from a mode corresponding to the disclosed horizontal vibration. However, the oil damper requires maintenance such as deterioration of an oil sealing portion and oil leakage, and the device is expensive.

Japanese Patent Application Laid-Open No. 9-67877 discloses a technique of a vibration damping floor panel in which a vibration absorber such as a chain or gravel is added to a floor joist or a beam. The technique disclosed in the publication is to provide an inexpensive and maintenance-free vibration damping device by using chains and gravel.

[0006]

By combining the techniques of the above two publications, it is considered that there is a possibility that an inexpensive vibration damping device that can cope with minute amplitudes can be realized.
The structure of the vibration damping device was studied by combining a chain as a lever and a damper. An object of the present invention is to provide an inexpensive vibration damping device for small amplitudes having a large vibration damping effect.

[0007]

Means for Solving the Problems In order to solve the above problems, the present inventors have studied a vibration damping device using a chain as a damper, and have obtained the following knowledge.

(A) When a chain has a small amplitude, the energy absorption rate (decay rate) is small. When the amplitude exceeds one pitch of the chain ring, the attenuation rate saturates and stabilizes. (b) As the chain ring becomes smaller, the attenuation rate saturates at a smaller amplitude, but when the amplitude is increased and the chain is vibrated, the energy absorption becomes larger.

(C) Methods of expanding the amplitude include a method using a lever and a method using resonance. In the method using resonance, a vibration system may be configured by adding a spring for resonance to a chain or an aggregate of chains.

(D) In a vibration damping device using a chain as a damper, the vibration direction of the chain is limited to the vertical direction. If the horizontal movement of the weight is converted into the vertical movement of the damper part,
There is no restriction on the vibration direction.

Based on the above findings, the following invention has been completed. (1) A chain assembly for a damper, comprising a chain having a chain ring whose surface is roughened. (2) A chain assembly for a damper, comprising a chain having a plurality of types of chain pitches.

(3) A chain assembly for a damper, comprising a spring and a plurality of chains connected to one end of the spring. (4) The chain aggregate for a damper, wherein the chain according to the above (3) is a chain having a chain ring whose surface is roughened, or a chain having a plurality of kinds of chain ring pitches.

(5) The above-mentioned device suspended at the vibration point of the vibrating body
(1) The chain assembly for a damper according to any one of the items (4) to (4), and a chain collision body arranged to support a lower portion of the chain of the chain assembly for the damper, Vibration control device.

(6) A vibration damping device comprising a lever, a spring, a weight, a chain assembly for a damper according to any one of the above (1) to (4), and a chain collision body. Lever fulcrum has a horizontal axis of rotation, one end of the spring is connected to an arbitrary force point of the lever to keep the lever in a stationary state, and at least one of the fulcrum and the other end of the spring is The weight is coupled to the vibrating point of the vibrating body, and the weight is arranged so as to apply a relative displacement to the horizontal or vertical vibration of the vibrating body to one of the force points, and the damper chain assembly is moved in the horizontal direction of the lever The vibration damping device is suspended from a point of force on an extended arm, and the chain collision body is arranged to support a lower part of the chain of the damper chain assembly.

Here, the chain aggregate is a bundle formed by bundling one to several tens of chains and connecting one end or both ends of the tuft.
It is used in a suspended state or in a suspended state (catenary) at both ends.

The surface roughening treatment of the chain ring means using a chain material having irregularities in order to increase the friction coefficient, sand blasting, or coating with sand or other particles. This is a process for increasing the surface friction coefficient by about 30% or more as compared with a commercially available untreated product (bare or plated). The chain-ring pitch is the distance between the center of the chain-ring and the center of the adjacent chain-ring. Normally, a standardized chain having a large chain-ring pitch can be said to be a thick chain.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have studied the vibration damping characteristics of a chain when studying a vibration damping device using a chain as a damper.

FIG. 1 is a schematic diagram of an apparatus for testing the attenuation characteristics of a chain assembly. In the figure, a chain assembly 1 is formed by bundling several chains and connecting one end thereof. This chain assembly 1 is a load cell 2
1 and is suspended by the lifting device 22. The test was performed by raising and lowering the chain assembly 1 with the lifting device 22 with the lower end of the chain assembly 1 partially touching the chain collision body 6. The displacement x of the chain assembly 1 was read on the scale 20. FIG. 2 is a graph showing the relationship between the displacement x of the chain assembly 1 and the load w. As the chain assembly of the test piece, a steel chain shown in Table 1 was used.

[0019]

[Table 1]

The chain a in Table 1 is a chain used for general construction and handrails, and the surface of the chain ring is rust-proofed and zinc-plated, and b is a paint in which sand is mixed into the chain ring to increase the friction coefficient. The chain c is a bundle of thin chains, and the chain d is a bundle of thin chains mixed with ordinary chains.

The curve a1 in FIG. 2 is a displacement-load curve in the case where the amplitude is small in the chain a in Table 1, and the curve a2 in FIG. 2 is a case in which the amplitude is large in the same chain a. As shown in the figure, the displacement x and the load w draw a hysteresis curve. The area of the range enclosed by the hysteresis curve corresponds to one cycle of vibration energy absorption.

The curves b1, c1 and d1 are curves when the chains b, c and d in Table 1 are vibrated at the same small amplitude as a1. The curves b2, c2 and d2 are curves when vibrating at the same large amplitude as a2.

Comparing the similarity between the shapes of the curve a1 and the curve a2 in the figure, the shape of a1 is slim. That is, when the amplitude is small, the ratio of energy absorption is relatively small.

When the curves b2, c2, d2 and a2 are compared, they are almost the same. That is, when the amplitude is large, it is understood that the same energy absorption occurs in each chain. b1
When the curves b2 and b2 are compared, they are almost similar. That is, when the friction coefficient of the chain surface is large, the ratio of energy absorption is large even at a small amplitude.

When the curves of c1 and c2 are compared, they are almost similar. That is, a bundle of many thin chains having a small chain ring pitch has a large energy absorption ratio even at a small amplitude. When the curves of d1 and d2 are compared, they are almost similar. That is, it is understood that a thin chain having a small chain ring pitch absorbs energy of a small amplitude, and that of a large amplitude, energy is absorbed by both chains.

The reason why the chains having a large chain-ring pitch (thick chains) and the thin chains are mixed in the chain aggregate d shown in Table 1 is to reduce the cost. In other words, since the unit price of a thin chain is high, the idea is that when the amplitude is small, the chain is assigned to a thin chain, and when the amplitude is large, the chain is assigned to a thick chain.

FIG. 3 is a graph showing the relationship between the amplitude and the attenuation rate for each type of chain. FIG. 7 shows the attenuation rate in the ratio of the area of the hysteresis curve in FIG. 2 to the area of a rectangle surrounding the hysteresis curve.

As shown in the figure, the larger the amplitude, the larger the attenuation rate. In the chain a or c in Table 1, the attenuation rate is saturated at an amplitude of 1.5 or more pitches of the chain ring. You can see that. It can be seen that in the chain b in which the surface of the chain ring has been roughened, the attenuation at a small amplitude is larger.

As described above, when a chain assembly is used for the damping damper, the surface of the chain ring is roughened or mixed with a thin chain and a thick chain so that a small amplitude can be handled. It can be seen that it is effective to reduce the cost while responding to the amplitude.

As described above, when comfort is taken into consideration, vibrations of only a few mm may be uncomfortable. However, from the graph of FIG. . Thus, it is found that it is effective to temporarily increase the amplitude and then allow the chain aggregate to absorb energy.

FIG. 4 is a schematic view of a chain assembly with a spring according to the present invention. FIG. 4 (a) is a one-spring type in which the chain 1a is suspended by one spring, and FIG. 4 (b) is both ends of the chain 1a. Is connected to two springs 1b. In FIG. 1A, the chain assembly 1 forms a resonance system by the weight of several chains 1a and the spring constant of the spring 1b. In the figure, the lower part of the chain 1a is loaded on the chain collision body 6. Since this chain assembly is designed to have a natural frequency of about 2 Hz, which makes humans feel uncomfortable,
The vibration energy of the frequency can be effectively absorbed. Because this vibration system has nonlinear and statistical behavior,
Normal differential equation solving cannot be used. According to the test results of the inventors, as the mass used for calculating the natural frequency,
It is sufficient to expect 40 to 90% of the mass of the chain assembly. The chain used for this spring-attached chain assembly may be a chain composed of a chain obtained by roughening the surface of a chain ring, or a chain having a plurality of types of chain ring pitches, It may be a normal chain. As shown in FIG. 2B, the chain assembly 1 of the present invention may be a vibration system composed of two springs 1b and a suspended chain 1a. Can be used as excitation points. Further, a configuration in which a chain of chains is suspended by a plurality of springs is also possible as an example of the present invention.

Hereinafter, the chain assemblies with springs shown in FIGS. 4A and 4B and the chain assemblies using the chains b and d in Table 1 are collectively referred to as the chain assemblies of the present invention. On the other hand, a, c in Table 1
Are referred to as a chain aggregate other than the present invention or a chain aggregate of a comparative example. It is effective to use the chain assembly of the present invention as it is as a damper in a vibration system.

FIG. 5 is a schematic view showing an example in which the chain assembly of the present invention is directly applied to a damping floor panel as a damper for damping, and FIG. 5 (a) is disclosed in JP-A-9-67877. FIG. 4B shows a case where the chain of the damping floor panel disclosed in the publication is replaced with a chain assembly with a spring according to the present invention shown in FIG. 4B. In FIG. 1A, both ends and / or the center of a chain 9 are fastened to a joist 10 of a floor panel, and when vibration is applied to the floor panel, the chain 9 becomes a bottom plate 11 of the floor panel (a member called a chain collision body in the present invention). ) And absorb vibration energy.

Although the technique disclosed in the above publication alone is not sufficient for the vibration suppression effect of a minute amplitude, as shown in FIG. Is also possible. In the same figure (b), the chain assembly 1 is composed of the chain 1a and the spring 1
b.

In addition to the spring-loaded chain assembly shown in FIG. 3B, the chain assembly of the present invention in which the surface of the chain ring is roughened, or the damper of the present invention in which thin and thick chains are combined. Even when used as a chain assembly, there is a vibration damping effect with a very small amplitude.

The chain assembly of the present invention may be mounted on the vibration point of the vibrating body as it is, as in the example of FIG. 5, but in order to further suppress minute vibrations, the original amplitude must be increased after being enlarged. A damping means is required.

FIG. 6 is a schematic diagram of a vibration damping device according to the present invention.
In the figure, the chain assembly 1 is suspended at one point of force on the arm of the lever 2. A chain collision body 6 is disposed below the chain assembly 1 and bears a part of the load of the chain assembly 1. The fulcrum 3 of the lever 2 has a rotation axis in a direction (horizontal direction) perpendicular to the paper surface. The weight 4 is arranged at the other force point of the lever 2. One end of the spring 5 is connected to an arbitrary point of force on the lever 2, and the other end is fastened to a support structure integrated with the vibrator or an independent support structure. At least one of the lever 3 or the other end of the spring 5 is at the vibration point 8 of the vibrating body 7.
FIG. 2 shows a state in which the fulcrum 3 is coupled to the vibration point 8. The chain collision body 6 can have a plate shape, a bowl shape, or the like, and is supported by a structure integral with the vibration body 7 or a structure independent of the vibration body 7. The surface of the collision body 6 may be provided with a rubber lining or the like to prevent noise.

When the vibration damping device shown in FIG. 3 has a single structure, it may be housed in the outer case 12 and the fulcrum 3, the other end of the spring 5, and the chain colliding body 6 may be supported by members of the outer case 13. . Further, the outer box 12 may be mounted on the vibrating body 7.

The vibrating body 7 is a bridge, a beam structure, a floor, or the like. The vibration damping device of the present invention is installed in a place where vibration is greatest, for example, in a place near the vibration point such as the center of the beam. Good to do.

In FIG. 6, when the vibration is transmitted from the vibrating body 7 via the vibrating point 8, the lever 2 vibrates due to the inertia of the weight 4. The amplitude of the weight 4 is enlarged by the lever 2 and transmitted to the chain assembly 1 fastened to one point of force, so that vibration energy is consumed by friction of the chain and vibration of the vibrator 7 is suppressed. In addition, in the figure, the spring 5 is represented as a coil spring, but may be replaced by a torsion bar, a leaf spring, or a rubber elastic body, or may be a coil spring that generates a moment around a fulcrum, a torsion bar, or the like. It may be a leaf spring or a rubber elastic body. .

FIG. 7 is a schematic diagram showing another example of the vibration damping device of the present invention. FIG. 2A shows the weight 4 suspended below the fulcrum 3, and FIG. 2B shows the chain assembly 1 arranged on both sides of the lever 2 and the weight 4 suspended obliquely. It is. Same figure
In the example of (a), the weight 4 suppresses vibration in the horizontal direction (left and right on the paper surface). In the case of FIG. 5B, the weight 4 is arranged in an oblique direction, so that both the horizontal vibration damping effect and the vertical vibration damping effect are provided. In addition, the chain assembly 1 is disposed at the force points at both ends of the lever, and the damping characteristic around the balance point of the lever 2 is symmetrical around the fulcrum, so that it is easy to design,
The damping effect also has a high advantage.

[0042]

(Embodiment 1) JP-A-9-67 shown in FIG.
877 as a comparative example.
The chain of the damping floor panel shown in (b) was replaced with a chain assembly for a damper of the present invention (a suspension-type chain assembly with spring shown in FIG. 4 (b), without surface roughening of the chain). A comparative test of the damping effect was performed using the damping floor panel as an example of the present invention.

The vibration damping floor panel of the present invention is fixed on a vibrating table having springs at four corners, and has a natural frequency of 1.5 to 2.5H.
An additional weight was loaded on the shaking table so that z was obtained. The shaking table was pressed down to give an initial displacement of 20 mm, and the decay time of the amplitude of the shaking table was measured. The same test was performed on the vibration damping floor panel of the comparative example. Table 2 shows the test results.

[0044]

[Table 2]

As shown in Table 2, the damping effect of the damping floor panel using the damper chain assembly of the present invention was 6.4 s before the amplitude became 2 mm, whereas the damping effect was 10.6 s in the comparative example. It was big. In this case, the decay time was the same in both the present invention example and the comparative example up to an amplitude of about 10 mm, but when the amplitude was reduced, the decay time in the present invention example was shorter than the comparative example.

Example 2 The vibration damping device housed in the outer box 12 shown in FIG. 5 was fixed to a vibration table as in Example 1, and the type of the chain assembly 1 was changed to measure the vibration decay time. An additional weight was loaded on the shaking table so that the natural frequency of the shaking table was approximately 2 Hz. The shaking table was pressed down to give an initial displacement of 20 mm, and the decay time of the amplitude of the shaking table was measured.

The natural frequency of the weight 4, the spring 5, the lever 2, and the chain assembly 1 of the vibration damping device was adjusted to about 2 Hz. The lever arm length ratio between the weight side 4 and the chain assembly 1 side was 1: 5. The type of the chain assembly 1 is a chain assembly composed of the a, b, and d chains shown in Table 1 and a spring-attached chain assembly (shown as type e in Table 3) shown in FIG. Is a comparative example, b,
d and e are examples of the present invention.

Table 3 shows the test results.

[0049]

[Table 3]

As shown in Table 3, the decay time of the present invention example and the comparative example was equivalent to each other up to the amplitude of about 5 mm. On the other hand, in the example of the present invention. The time until the amplitude became small was short, and the vibration damping effect was high.

[0051]

When the chain assembly of the present invention is used as a damper for a vibration damping device, the vibration damping effect is large. Further, when the vibration damping device of the present invention is used for an additional vibration system of a vibrating body, an effective vibration damping effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus for testing the attenuation characteristics of a chain assembly.

FIG. 2 is a graph showing a relationship between displacement and load of a chain assembly.

FIG. 3 is a graph showing the relationship between the amplitude and the attenuation rate of a chain assembly.

FIGS. 4A and 4B are schematic views of a chain assembly with a spring according to the present invention, wherein FIG. 4A shows a one-spring type and FIG.

FIG. 5 is a schematic diagram of a case where the chain assembly of the present invention is applied to a vibration-damping floor panel.

FIG. 6 is a schematic diagram of a vibration damping device according to the present invention.

FIG. 7 is a schematic diagram of another example of the vibration damping device of the present invention.

[Explanation of symbols]

 Reference Signs List 1 chain assembly 1a chain 1b spring 2 lever 3 fulcrum 4 weight 5 spring 6 chain collision body 7 vibrator 8 vibration point 9 chain 10 joist 11 bottom plate 12 outer box 20 scale 21 load meter 22 lifting device

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code FI F16F 7/10 F16F 7/10 15/02 15/02 E (72) Inventor Yasutomo Yanagimoto 4-5 Kitahama, Chuo-ku, Osaka-shi No. 33 Sumitomo Metal Industries Co., Ltd. (72) Inventor Yukio Abe 4-5-33 Kitahama, Chuo-ku, Osaka-shi Sumitomo Metal Industries Co., Ltd.

Claims (6)

[Claims] 1. A chain assembly for a damper, comprising a chain having a chain ring whose surface is roughened. 2. A chain assembly for a damper, comprising chains of a plurality of types of chain-ring pitches. 3. A chain assembly for a damper, comprising: a chain; and a spring connected to one or both ends of the chain. 4. A chain aggregate for a damper, wherein the chain according to claim 3 is a chain having a chain ring whose surface is roughened, or a chain having a plurality of types of chain ring pitches. 5. The apparatus according to claim 1, wherein the vibrating body is suspended at a vibration point.
5. A vibration damping device, comprising: the chain assembly for a damper according to any one of claims 4 to 4; and a chain collision body arranged to support a lower portion of a chain of the chain assembly for a damper. 6. A lever, a spring, a weight, and a weight.
A chain assembly for a damper according to any one of the above, and a chain collision body, wherein the fulcrum has a horizontal rotation axis, and one end of the spring is connected to an arbitrary force point of the lever. The stationary lever is kept in balance, and at least one of the fulcrum and the other end of the spring is coupled to the vibration point of the vibrating body, and the weight is moved in at least one of the horizontal and vertical directions of the vibrating body. The damper chain assembly is suspended so as to apply a relative displacement to the vibration to the one force point, and the chain assembly for the damper is suspended at the force point on the arm extending in the horizontal direction of the lever, and the chain collision body is connected to the chain assembly for the damper. A vibration damping device arranged to support a lower part of a body chain.